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DNA-binding affinity and transcriptional activity of the RelA homodimer of nuclear factor κB are not correlated
- Source :
- The Journal of biological chemistry, vol 292, iss 46
- Publication Year :
- 2017
- Publisher :
- Elsevier BV, 2017.
-
Abstract
- The nuclear factor κB (NF-κB) transcription factor family regulates genes involved in cell proliferation and inflammation. The promoters of these genes often contain NF-κB-binding sites (κB sites) arranged in tandem. How NF-κB activates transcription through these multiple sites is incompletely understood. We report here an X-ray crystal structure of homodimers comprising the RelA DNA-binding domain containing the Rel homology region (RHR) in NF-κB bound to an E-selectin promoter fragment with tandem κB sites. This structure revealed that two dimers bind asymmetrically to the symmetrically arranged κB sites at which multiple cognate contacts between one dimer to the corresponding DNA are broken. Because simultaneous RelA-RHR dimer binding to tandem sites in solution was anti-cooperative, we inferred that asymmetric RelA-RHR binding with fewer contacts likely indicates a dissociative binding mode. We found that both κB sites are essential for reporter gene activation by full-length RelA homodimer, suggesting that dimers facilitate DNA binding to each other even though their stable co-occupation is not promoted. Promoter variants with altered spacing and orientation of tandem κB sites displayed unexpected reporter activities that were not explained by the solution-binding pattern of RelA-RHR. Remarkably, full-length RelA bound all DNAs with a weaker affinity and specificity. Moreover, the transactivation domain played a negative role in DNA binding. These observations suggest that other nuclear factors influence full-length RelA binding to DNA by neutralizing the transactivation domain negative effect. We propose that DNA binding by NF-κB dimers is highly complex and modulated by facilitated association-dissociation processes.
- Subjects :
- Models, Molecular
0301 basic medicine
cooperativity
Cooperativity
Crystallography, X-Ray
Medical and Health Sciences
Biochemistry
Mice
chemistry.chemical_compound
Transactivation
0302 clinical medicine
Models
Transcription (biology)
Promoter Regions, Genetic
Crystallography
dimerization
RELA
E-selectin
Biological Sciences
Cell biology
Protein Structure and Folding
E-Selectin
Protein Binding
Transcriptional Activation
crystal structure
Biochemistry & Molecular Biology
kB site
1.1 Normal biological development and functioning
DNA transcription
RelA
Biology
Promoter Regions
03 medical and health sciences
Genetic
Protein Domains
Underpinning research
Genetics
Animals
Molecular Biology
Transcription factor
Binding Sites
Base Sequence
Transcription Factor RelA
Molecular
Promoter
DNA
Cell Biology
Molecular biology
DNA binding site
030104 developmental biology
Gene Expression Regulation
chemistry
Chemical Sciences
X-Ray
Generic health relevance
Protein Multimerization
030217 neurology & neurosurgery
NF-kB transcription factor
Subjects
Details
- ISSN :
- 00219258
- Volume :
- 292
- Database :
- OpenAIRE
- Journal :
- Journal of Biological Chemistry
- Accession number :
- edsair.doi.dedup.....9985ca1a887b51ed4b89755733b9d0e2